Records of the Western Australian Museum 18: 347-355 (1998).

The water mite family Limnesiidae from northern and Western (Acari: Actinedida), with a description of two new species

Harry Smit Emmastraat 43-a, 1814 OM Alkmaar, The Netherlands

Abstract - Two new species, Linmesia r!lbra and Physolin1l1esia katherine, are described from the , Australia. Timmsilinmesia prehendens is synonymized with Limnesia inga. Additional taxonomic characteristics are given for L parasolida and L solida. Furthermore, new records are presented from the Northern Territory and Western Australia for a number of Limnesia species known from other regions of Australia.

INTRODUCTION ments of paratypes are given in brackets. The The family Limnesiidae is represented in following abbreviations have been used: PI-PV Australia by five genera: Heterolimnesia, Limnesia, palp segments 1-5; I-Ieg-5 fifth segment of first leg. Physolimnesia, Timmsilimnesia and Tubophorella (Cook, 1986). The most species-rich genus is Limnesia, with 25 species known from Australia so SYSTEMATICS far. Genus Limnesia Koch Limnesiid water mites occur in nearly every lentic water of Northern Territory and Western Limnesia Koch, 1836: 19. Australia. Together with members of the genus Arrenurus (Srnit, 1997), they belong to the most abundant water mites of these type of waters Limnesia (Limnesia) lembangensis Piersig (personal observation). Limnesia lembangensis Piersig, 1906: 348; Waiter, In this study, two new species are described, 1928: 73; WaIter, 1929: 228; K Viets, 1935: 607; Limnesia rubra and Physolimnesia katherine. New Uchida, 1935: 121; Halik, 1941: 109; KO. Viets, records are presented of Linmesia inga KG. Viets, 1959: 422; Imamura, 1964: 70; Cook, 1967: 87; L. lembangensis Piersig, L. longigenitalis Lundblad, Lundblad, 1969: 334; Prasad, 1974: 62; KO. L. maceripalpis KO. Viets, L. parasolida KO. Viets, Viets, 1975: 93; Bisht, 1979: 89; Khatoon and Ali, L. solida Lundblad and Timmsilinmesia prehendens 1989: 613; Smit, 1992: 95. KO. Viets. Timmsilimnesia prehendens proved to be Limnesia gentilis Koenike, 1906: 124. the male of Limnesia inga, a species previously known only from the female; the new name is Limnesia gentilis indica K Viets, 1926: 378. Timmsilimnesia inga (K.O. Viets). Additional taxonomic characteristics are given for two Material Examined previously inadequately described species, L. Australia: Northern Territory: 1 'jl, Lake Jabiru, parasolida and L. solida. Jabiru, 20 July 1994; 6 0,5 'jl, 1 nymph, billabong Yellow Waters, , 21 July 1994. MATERIAL AND METHODS All material has been collected by the author. Remarks Holotypes and paratypes from the Northern Unlike specimens from eastern Australia, which Territory have been deposited in the Northern have red chitinized parts (Halik, 1941; personal Territory Museum (Darwin) (NTM). Additional observation), those of Northern Territory have paratypes have been deposited in the Western brown chitinized parts. Australian Museum (Perth) (WAM) and the Zoological Museum of the University of Distribution Amsterdam (ZMA). All non-type material has been Previously reported from New South Wales placed in the ZMA. (Halik, 1941) and Queensland (Smit, 1992). L Measurements of palp and leg segments are lembangensis has a very wide distribution, and is dorsal lengths. The body length is measured known from Taiwan, Singapore, Thailand, India, dorsally from unmounted specimens. Measure- Pakistan, Sri Lanka and Indonesia. 348 H. Smit

Limnesia (Limnesia) longigenitalis Lundblad Limnesia (Limnesia) parasolida K.O. Viets Figure 1 Limnesia longigenitalis Lundblad, 1941a: 114; Lundblad, 1947: 42; Smit, 1992: 95. Limnesia parasolida KO. Viets, 1984: 419; Cook, 1986: 76; Smit, 1992: 95. Material Examined Australia: Western Australia: 4 0, 12 9, 2 Material Examined nymphs, ditch pastoral land, Peaceful Bay, Australia: Northern Territory: 4 0, 7 9, Radon southwest of Denmark, 30 August 1994; 1 9, Lake Springs, Kakadu National Park, 19 July 1994; 8 0, Seppings, Albany, 31 August 1994. 6 9, billabong Nourlangie Creek, Kakadu National Park, 20 July 1994; 3 0,2 9, Lake Jabiru, Jabiru, 20 Remarks July 1994; 19 0, 24 9, 3 nymphs, Baroalba Springs The females of this study measure 1188-1296 in (Gubarra), Kakadu National Park, 20 July 1994; 2 length, the males 698-737 in length. Lundblad 9, Mardugal Billabong, Kakadu National Park, 21 (1947) mentioned the following lengths: male 690, July 1994; 3 9, 5 nymphs, pond in Jim Jim Creek, female 1345. at Jim Jim Crossing, Kakadu National Park, 22 July 1994; 1 9, Home Billabong, Kakadu National Park, Distribution 22 July 1994; 8 0, 15 9, pool near , Previously reported from Victoria (Lundblad, Kakadu National Park, 23 July 1994; 4 0, 2 9, 1 1947) and New South Wales (Smit, 1992). In this nymph, pond Jim Jim Creek, at Jim Jim study, the species has been found only in the campground, Kakadu National Park, 23 July 1994; southwestern part of Western Australia. 1 9, pool Twin Falls, Kakadu National Park, 23 July 1994; 1 9, Barramundie Creek, Kakadu National Park, 24 July 1994; 2 0, 5 9, 1 nymph, pools upstream of Waterfall Creek, Kakadu Limnesia (Limnesia) maceripalpis K.O. Viets National Park, 25 July 1994; 14 0, 1 9, 3 nymphs, Limnesia maceripalpis KO. Viets, 1975: 93; KO. plunge pool , Kakadu National Park, Viets, 1984: 421; Cook, 1986: 77. 25 July 1994; 1 0, Southern Rockhole, Katherine Gorge National Park, 27 July 1994; 11 0, 9 9, 1 Material Examined nymph, Lily Ponds Falls, Katherine Gorge National Australia: Northern Territory: 1 9, Radon Springs, Kakadu National Park, 19 July 1994; 1 0, Baroalba Springs (Gubarra), Kakadu National Park, 20 July 1994; 2 0, 2 9, 1 nymph, Lake Jabiru, Jabiru, 20 July 1994; 2 0, pool Twin Falls, Kakadu National Park, 23 July 1994; 1 9, pools upstream of Waterfall Creek, Kakadu National Park, 25 July 1994; 2 0, 1 9, Southern Rockhole, Katherine , 01 Gorge National Park, 27 July 1994; 6 0, 3 9, plunge pool , Katherine Gorge National Park, 30 July 1994. Western Australia: 1 9, Palm Pool, Millstream­ Chichester National Park, 15 August 1994; 1 0, 3 9, pond Snake Creek, Millstream-Chichester National Park, 17 August 1994; 3 9, Ashburton River, at crossing with North West Coastal Highway, 18 August 1994; 3 9, 1 nymph, Fortescue f River, at crossing with North West Coastal I Highway, 18 August 1994.

Remarks The largest male of this study measured 1320 in length, the largest female 1536. Cook (1986) gave the following measurements: males 760-851 and o females 927-1075.

Distribution 1 Previously reported from Queensland (K.O. Viets, 1975; Cook, 1986) and the Northern Territory Figure 1 Limnesia parasolida K.O. Viets: 1, dorsal view, (KO. Viets, 1984). o. Scale line = 200 pm. Limnesiidae from northern and Western Australia 349

Park, 27 July 1994; 9 6, 6 ,?, 1 nymph, small measurements: females 638-850, males 760-896. stream, Butterfly Gorge, Katherine Gorge National Small specimens usually have a short terminal seta Park, 27 July 1994; 2 6, 1 ,?, 1 nymph, Katherine on IV-Ieg-6, 77-84 in length. In larger specimens River, near visitor's center, Katherine Gorge this seta measures 127-137. However, intermediate National Park, 28 July 1994; 1 '?, pond Chinaman lengths do occur. It might be possible that more Creek, 16 km south of Katherine, 29 July 1994; 6 6, than one species is present, but morphological 7 ,?, 1 nymph, plunge pool Edith Falls, Katherine characters do not allow a separation. Gorge National Park, 30 July 1994; 3 6, 1 ,?, Douglas River, at Douglas Hot Springs, 1 August Distribution 1994; 1 6, 1 ,?, ponds Ormiston Gorge, Ormiston Previously reported from Northern Territory Gorge National Park, 6 August 1994; 3 6, (AliceSprings area) (K.O. Viets, 1984) and waterhole Ormiston Gorge, Ormiston National Queensland (Cook, 1986; Smit, 1992). With the new Park, 6 August 1994. records, it can be concluded that L. parasolida is a Western Australia: 8 6, 26 '?, 3 nymphs, common species of the northern half of Australia. Fortescue Falls (pool), Hamersley Range National Park, 11 August 1994; 5 6, 12 ,?, 12 nymphs, pond Dales Gorge, Hamersley Range National Park, 12 August 1994; 14 6, 12 <:(, 5 nymphs, pond Limnesia (Limnesia) rubra sp. novo Kalamina Gorge, near falls, Hamersley Range Figures 2-4 National Park, 13 August 1994; 2 6, streams Material Examined originating in Chinderwariner Pool, Millstream­ Chichester National Park, 15 August 1994; 4 Holotype nymphs, Palm Pool, Millstream-Chichester 6, plunge pool Edith Falls, Katherine Gorge National Park, 15 August 1994; 2 nymphs, Deep National Park, Northern Territory, Australia, 30 Reach Pool, Millstream-Chichester National Park, July 1994 (NTM). 15 August 1994; 2 nymphs, western part Deep Reach Pool, Millstream-Chichester National Park, Para types 16 August 1994; 2 6,2 <:(, Python Pool, Millstream­ 1 6, 1 '? (ZMA), 1 '? (NTM), same data as Chichester National Park, 17 August 1994; 5 6, 1 holotype. <:(, Jones River, east of Roeburne, 17 August 1994; 3 6, 2 ,?, 2 nymphs, Fortescue River, at crossing with Diagnosis North West Coastal Highway, 18 August 1994; 2 Male acetabular plates forming a complete ring 6, Ashburton River, at crossing with North West Coastal Highway, 18 August 1994. surrounding the gonopore, extensive secondary sclerotization around fourth coxal plates and genital field, first coxal plates fused medially, Remarks capitular bay deep, Glandula Limnesiae on third In some populations, males and females coxal plates and well separated from associated possessing an aberrant number of acetabula, co­ setae, peg-like seta on ventral margin of PH not on occur with specimens having the normal two pairs a tubercle, legs with swimming setae, chitinized of three acetabula. The following aberrant numbers parts coloured red. of acetabula have been recorded (males as well as females): 2+2, 2+3, 7+7 and 8+8. All these Description specimens are otherwise similar to L. parasolida, so I assigned them to that species. The number of Male acetabula is used for subgeneric splitting within Body 1067 (989) long and 902 (873) wide; the genus Limnesia, e.g. tetracetabulate species are chitinized parts coloured red. Integument smooth. assigned to Tetralimnesia. It is clear that the number Dorsum with an elongated platelet, 136 (136) in of acetabula cannot be used for subgeneric length. Capitular bay deep, longer than medial splitting. Cook (1974) has pointed out the margins of first coxal plates. First coxal plates likelihood that unrelated species are lumped in fused medially. Glandula Limnesiae on third coxal subgenera of Limnesia. plates, well separated from the associated setae. Occasionally, the IV-Ieg-5 of L. parasolida has two Extensive secondary sclerotization around fourth stiff swimming setae. Cook (1986) mentioned the coxal plates and genital field, and to a lesser extent occurrence of only one stiff setae on this leg medial of third coxal plates and posterior of first segment. coxal plates. Gonopore 136 (120) long, completely L. parasolida shows large variation in length. surrounded by acetabular plates. Genital field with Females range from 320 to 1344 in length, the lower two pairs of three acetabula, the most anterior pair value belonging to a young female. Males ranged elongated. Excretory pore between associated from 523 to 912. Cook (1986) gives the following glandularia. Lengths of PI-PV: 29, 144, 91, 206, 60. 350 H. Smit

2 3

G

4

i r

Figures 2-4 Limnesia rubra sp. nov., holotype 0: 2, ventral view; 3, palp <3; paratype '?: 4, ventral view. Scale lines: 2, 4 200 pm; 3 = 100 pm. Limnesiidae from northern and Western Australia 351

Peg-like seta of ventral margin of PH not on a waterhole Kantju Gorge, Ayers Rock, 4 August tubercle; setal tubercles of PIV small. Lengths of 1­ 1994; 1 <;>, ponds Ormiston Gorge, Ormiston Gorge leg-4-6: 142, 166, 132. Lengths of IV-leg-4-6: 216, National Park, 6 August 1994. 233, 214; distal seta of IV-leg-6 142 long. III-leg-4 Western Australia: 7 0, 9 <;>, 1 nymph, Fortescue with one, III-leg-5 with nine, IV-leg-4 with four and Falls (pool), Hamersley Range National Park, 11 IV-leg-5 with two long swimming setae. August 1994; 2 0, 7 <;>, 5 nymphs, Circular Pool, Hamersley Range National Park, 12 August 1994; 1 Female <;>, pond Dales Gorge, Hamersley Range National Body 1212-1397 long and 1018-1096 wide. Park, 12 August 1994; 3 0, 2 <;>, 1 nymph, pond Dorsum with an elongated platelet, 184-213 long. Knox Gorge, Hamersley Range National Park, 13 First coxal plates fused medially. A strip of August 1994; 9 0, 17 <;>, 1 nymph, pool Joffre secondary sclerotization ~long coxal plates . Gorge, Hamersley Range National Park, 13 August Gonopore 194 long. Genital field with two pairs of 1994; 11 0, 5 <;>, 2 nymphs, pond Kalamina Gorge, three acetabula. A genital sclerite 204 in width, near falls, Hamersley Range National Park, 13 anterior of genital field. Excretory pore between August 1994; 2 <;>, Handrail pool, Weena Gorge, associated glandularia. Palp as in male; lengths of Hamersley Range National Park, 14 August 1994; PI-PV: 36, 146, 118, 233, 34. Lengths of l-leg-4-6: 10 0, 15 <;>, pond Hancock Gorge, Hamersley 166, 194, 156. Lengths of IV-leg-4-6: 242, 272, 252; Range National Park, 14 August 1994; 8 0, 6 <;>, 3 length of distal seta of IV-leg-6 146. III-Ieg-4 with nymphs, Palm Pool, Millstream-Chichester one, III-Ieg-5 with eight, IV-leg-4 with four and IV­ National Park, 15 August 1994; 2 <;>, 1 nymph, leg-5 with three long swimming setae. small pond near Crossing Pool, Millstream­ Chichester National Park, 16 August 1994; 1 <;>, Remarks Crossing Pool, Millstream-Chichester National The new species belongs to the solida-group (L. Park, 16 August 1994; 11 0, 4 <;>, Python Pool, australica Lundblad, L. parasolida, L. solida) of Cook Millstream-Chichester National Park, 17 August (1986). The only other species of that group with 1994; 18 0, 27 <;>, 1 nymph, McKenzie Spring, the Glandula Limnesiae well separated from the Millstream-Chichester National Park, 17 August associated setae, L. parasolida, has the gonopore as 1994; 14 0, 6 <;>, pond Snake Creek, Millstream­ large as the genital field and less extensive Chichester National Park, 17 August 1994; 5 0, 4 secondary sclerotization. Further, L. rubra has long <;>, 1 nymph, Jones River, east of Roeburne, 17 swimming setae (as in australica), while parasolida August 1994; 1 0, 1 <;>, 2 nymphs, Fortescue River, and solida have stiff swimming setae. The at crossing with North West Coastal Highway, 18 combination of long swimming setae and well August 1994; 1 0, 17 <;>, Ashburton River, at separated Glandula Limnesiae and associated setae will separate the female from other females of the solida-group.

Etymology Named for its conspicuous red colour. ®, ,'@ Limnesia (Limnesia) solida Lundblad ® @j Figure 5 Limnesia solida Lundblad, 1947: 46; K.O. Viets, 1975: @ 93; Smit, 1992: 95. I ~ I cq Material Examined @ ~© Australia: Northern Territory: 1 0, Home Billabong, Kakadu National Park, 22 July 1994; 1 <;>, Jim Jim Billabong, at crossing with Kakadu Highway, Kakadu National Park, 22 July 1994; 2 0, pond Jim Jim Creek, at Jim Jim campground, Kakadu National Park, 23 July 1994; 2 0, pools upstream of Waterfall Creek, Kakadu National Park, 25 July 1994; 1 0, 3 <;>, Kambolgie Creek, o Kakadu National Park, 26 July 1994; 1 <;>, Southern 5 Rockhole, Katherine Gorge National Park, 27 July 1994; 4 0, 3 '2, 1 nymph, billabong near Douglas Figure 5 Limnesia solida Lundblad, dorsal view, cl. Hot Springs, 1 August 1994; 6 0, 14 '2,1 nymph, Scale line 200 !lm. 352 H.Smit crossing with North West Coastal Highway, 18 Para types August 1994. 3 6', 2 9 (NTM), 2 6', 2 9 (WAM), 2 6', 2 9, 1 nymph (ZMA), same data as holotype. Remarks According to Cook (1986) L. solida and L. Diagnosis parasolida differ in the number of stiff swimming Male and female with four pairs of large setae on IV-Ieg-5 (solida with two setae and acetabula, gonopore much shorter than length of parasolida with one). However, the number of stiff genital field; third and fourth legs of male setae on IV-Ieg-5 varies in both species from 1-2, modified. Seta on ventral margin of second palp and can therefore not be used to separate the two segment on a tubercle; fourth palp segment with species. The two species are easily separated by the distinct setal tubercles. platelet on the dorsum, which is larger and more rounded in L. parasolida (Figure 1), and the distance Description between the Glandula Limnesiae and the associated seta (large in parasolida, short in solida). Male In contradiction to Smit (1992), the male does has a Body 776 (630-863) long and 562 (495-592) wide. platelet on the dorsal shield (Figure 5), 68-86 long. Dorsal platelets absent. First coxal plates not fused Males of L. parasolida have the gonopore as long as medially, but secondary sclerotization present the genital field, in L. solida the gonopore is between first coxal plates. Glandula Limnesiae distinctly shorter than the genital field. medial of suture line of third and fourth coxal The seta associated with coxoglandularia 2 of L. plates; associated setae close to Glandula solida are not always closer to the genital field (as Limnesiae. Genital field with four pairs of large stated by Cook), but occasionally halfway between acetabula. Gonopore 77 long, much shorter than the genital field and the coxoglandularia 2. Males genital field. Excretory pore between associated of solida sometimes show some secondary glandularia. Measurements of PI-PV: 19, 125, 89, sclerotization posterior of the genital field and 175,50. Seta on ventral margin of PH on a tubercle, fourth coxal plates. Males of this study are 737-941 seta longer than tubercle. Ventral margin of PIV in length, the long seta of IV-Ieg-6 measured 62-98 with distinct setal tubercles. Third and fourth legs in length. Females measured 902-1260 in length. modified. III-Ieg-6 expanded and flattened, with The nymphs of the two species can be separated one seta on medial side. IV-Ieg-5 large, with three with the platelet on the dorsal shield, which is 17­ long, thick setae and eight short, fine setae on 33 long in L. solida and 48-70 in L. parasolida. ventral margin, a row of hyaline setae on anteroventral margin, 11 (11-14) setae on medial Distribution side and three long setae on anterior part of A widespread species in Australia, previously segment; distal margin with one curved seta. IV­ reported from Victoria (only one record, the leg-6 ventrally with a row of grooves, anterodorsal holotype) and Queensland (K.O. Viets, 1975; Smit, margin with a group of curved setae, a group of 1992). The species is much more common in the fine setae on medial side and anteroposteriorly Northern Territory and Western Australia with a 161 long seta. Measurements of first, third compared to Queensland and Victoria. So far, no and fourth legs: I-Ieg-4-6: 154, 146, 144, I-Ieg-6 with records are known from the southwestern part of an undulating ventral margin. III-Ieg-4-6: 240, 236, Western Australia. 199. IV-Ieg-4-6: 228, 388, 248. Second, third and fourth legs with swimming setae.

Female Genus Physolimnesia Halik Body 553-1018 long and 456-795 wide. Dorsal Centrolimnesia (Physolimnesia) Halik, 1940: 21. platelets absent. Position of Glandula Limnesiae as in male. Genital field with two pairs of four, large Physolimnesia Halik: Lundblad, 1941b: 365. acetabula. Palp as in male. Measurements of PI-PV: 22, 125, 60, 173, 53. Measurements of I-Ieg-4-6: 115, 125, 120. Measurements of IV-Ieg-4-6: 211, 223, 218; Physolimnesia katherine sp. novo IV-Ieg-6 with a 132 long seta. Third and fourth legs Figures 6-10 with swimming setae. Material Examined Remarks Holotype Now that the second Physolimnesia species is 6', Southern Rockhole, Katherine Gorge National known, the diagnosis of the genus has to be Park, Northern Territory, Australia, 27 July 1994 altered: genital field with three or four pairs of (NTM). acetabula. The new species differs from Limnesiidae from northern and Western Australia 353

7 ~I~ 6

8

10

Figures 6-10 Physolimnesia katherine sp. nov., paratype 6: 6, ventral view; holotype 6: 7, palp; 8, II1-leg-5-6; 9, IV-Ieg­ 4-6; paratype Cjl: 10, ventral view. Scale lines: 6, 10 200 J..Im; 7, 8, 9 100 J..Im. 354 H. Smit

Physolimnesia australis (Halik) in having four pairs Territory (Palmerston) for their permission to of large acetabula (three in P. australis), and a more collect water mites in the national parks of Western slender III-Ieg-6 of the male. The row of 11-14 seta Australia and Northern Territory and to G.M. van on the medial side of IV-Ieg-5 is absent in australis, der Pal for her assistance with the fieldwork. but in general the modified third and fourth legs of the two species are remarkably similar. REFERENCES Bisht, RS. (1979). Limnesia lembangensis Piersig (Acarina) Etymology on two aquatic Hydrophilidae from Bhimtal, India. Named after the Katherine River, which is near Geobios 6: 89-90. the type locality; the name is a noun in apposition. Cook, D.R (1967). Water mites from India. Memoirs of the American Entomological Institute 9: 1-411. Cook, D.R. (1974). Water mite genera and subgenera. Genus Timmsilimnesia K.O. Viets Memoirs of the American Entomological Institute 21: 1­ Timmsilimnesia KO. Viets, 1984: 422. 860. Cook, D.R (1986). Water mites from Australia. Memoirs of the American Entomological Institute 40: 1-568. Timmsilimnesia inga (K.O. Viets), new Halik, L. (1940). Neue Wassermilben aus dem combination indoaustralischen Faunengebiete. Zoologischer Anzeiger 132: 279-284. Limnesia inga KO. Viets, 1975: 94. Halik, L. (1941). Beitrag zur Kenntnis der Timmsilimnesia prehendens K.O. Viets, 1984: 422. Wassermilbenfauna Australiens. Sbornfk New synonymy. Entomologickelo Oddeleni Zemskeho Musea v Praze 19: 103-118. Material Examined Imamura, T. (1964). Water-mites (Acari, Hydrachnellae) Australia: Northern Territory: 1

Viets, K. (1926). Indisehe Wassermilben. Zoologiselze (Hydrachnellae, Acari) aus Australien. Gewiisser lllld falzrblielzer, Abteilllng fllr Systematik 52: 369-394. Abwiisser 66/67: 143-169. Viets, K. (1935). Die Wassermilben von Sumatra, Java Viets, K.O. (1984). Ober Wassermilben (Acari, und Bali naeh den ergebnissen der Deutschen Hydrachnellae) aus Australien. Arc/liv fllr Limnologisehen Sunda-Expedition. Arc/liv fiir Hydrobiologie 101: 413-436. Hydrobiologie, SlIpplement 13: 595-738. Waiter, C. (1928). Zur Kenntnis der Mikrofauna von Viets, K.O. (1959). Wassermilben (Hydraehnellae) aus British Indien. Records of the Indian MlIsellm 30: 57­ dem indo-australisehen Faunengebiet. Archiv filr 108. Hydrobiologie 55: 415-428. Waiter, C. (1929). Hydracarinen aus Java. Trellbia 11: Viets, K.O. (1975). Neue Wassermilben (Acari, 211-273. Hydrachnellae) aus Australien. Zoologica Scripta 4: 93-100. Manllscript received 19 February 1997; accepted 24 filly Viets, K.O. (1980). Weitere Wassermilben 1997.